static char *sccsid = "@(#)dmesg.c 4.2 (Berkeley) 83/01/02"; /* * Suck up system messages * dmesg * print current buffer * dmesg - * print and update incremental history */ #include <stdio.h> #include <sys/param.h> #include <nlist.h> #include <signal.h> #include <sys/vm.h> #include <sys/msgbuf.h> struct msgbuf msgbuf; char *msgbufp; int sflg; int of = -1; struct msgbuf omesg; struct nlist nl[2] = { { "_msgbuf" }, { "" } }; main(argc, argv) char **argv; { int mem; register char *mp, *omp, *mstart; int timeout(); int samef; signal(SIGALRM, timeout); alarm(30); if (argc>1 && argv[1][0] == '-') { sflg++; argc--; argv++; } if (sflg) { of = open("/usr/adm/msgbuf", 2); read(of, (char *)&omesg, sizeof(omesg)); lseek(of, 0L, 0); } sflg = 0; nlist(argc>2? argv[2]:"/vmunix", nl); if (nl[0].n_type==0) done("No namelist\n"); if ((mem = open((argc>1? argv[1]: "/dev/kmem"), 0)) < 0) done("No mem\n"); lseek(mem, (long)nl[0].n_value, 0); read(mem, &msgbuf, sizeof (msgbuf)); if (msgbuf.msg_magic != MSG_MAGIC) done("Magic number wrong (namelist mismatch?)\n"); mstart = &msgbuf.msg_bufc[omesg.msg_bufx]; omp = &omesg.msg_bufc[msgbuf.msg_bufx]; mp = msgbufp = &msgbuf.msg_bufc[msgbuf.msg_bufx]; samef = 1; do { if (*mp++ != *omp++) { mstart = msgbufp; samef = 0; pdate(); printf("...\n"); break; } if (mp == &msgbuf.msg_bufc[MSG_BSIZE]) mp = msgbuf.msg_bufc; if (omp == &omesg.msg_bufc[MSG_BSIZE]) omp = omesg.msg_bufc; } while (mp != mstart); if (samef && omesg.msg_bufx == msgbuf.msg_bufx) exit(0); mp = mstart; do { pdate(); if (*mp && (*mp & 0200) == 0) putchar(*mp); mp++; if (mp == &msgbuf.msg_bufc[MSG_BSIZE]) mp = msgbuf.msg_bufc; } while (mp != msgbufp); done((char *)NULL); } done(s) char *s; { register char *p, *q; if (s && s!=(char *)omesg.msg_magic && sflg==0) { pdate(); printf(s); } write(of, (char *)&msgbuf, sizeof(msgbuf)); exit(s!=NULL); } pdate() { extern char *ctime(); static firstime; time_t tbuf; if (firstime==0) { firstime++; time(&tbuf); printf("\n%.12s\n", ctime(&tbuf)+4); } } timeout() { done("Buffer file screwed up\n"); }